The storage reserves in the mature seeds of eleven
species of Pinus were investigated. Lipids and proteins 1
sequestered in lipid vesicles and protein bodies respectively 1
were found to be the major storage reserves of pine seeds.
All seed tissues of mature Pinus seeds contained protein
bodies with one or more protein crystalloids andjor one or
more globoid crystals. Energy dispersive x-ray (EDX) analysis
of globoid crystals in all species of Pinus that were studied
revealed the presence of P 1 K and Mg 1 a fact that is
consistent with globoid crystals being phytate-rich. Traces
of Ca and Fe were also detected in the globoid crystals of
some seed tissues.
High levels of Fe and significant levels of P1 K and
Mg were detected in small (often .:::; 0. 3 3 J,£m) 1 naturally
electron-dense particles that were distributed throughout the
tissues of the embryo and female gametophyte. Unlike
conventional phytate-rich globoid crystals 1 these Fe-rich
particles were not contained in the proteinaceous matrix of
typical protein bodies. Instead 1 the particles were contained
within membrane-bound structures resembling plastids.
Neutron activation analysis and spectrophotometric
phosphorus analysis were used to provide a quantitative
determination of elements in whole female gametophyte and
embryo tissue samples. High levels of P, K, Mg and S and
significant levels of Cl, Ca, Mn, Zn and Fe were detected in
pine seed tissues. Environment and growth conditions under
which the seed developed did not appear to affect the total
mineral nutrient levels of mature pine seeds.
Seed size and weight varied greatly between the eleven
species of Pinus investigated. A major focus of this study
was to determine whether seed size was correlated to the
distribution of minerals in pine seeds. Previous studies
showed that mineral distribution was related to seed size in
cucurbits. Phosphorus, Mg and Ca concentrations in globoid
crystals and Fe concentrations in electron-dense particles of
Pinus seed tissue were found to be negatively correlated with
seed size.
A comparative study of nutrient reserves in haploid
female gametophyte tissue versus diploid embryo tissues was
made. Within each species of Pinus, the total mineral
nutrient concentrations in whole female gametophyte samples
were similar to total mineral nutrient concentrations within
whole embryo samples. Protein body structure and the types of
mineral nutrients stored in globoid crystals of protein bodies
were also similar between female gametophytes and their corresponding embryos.